—— 201 —— 
1 left haul n aro ambiguous, since tliev do not say 
Whicl Tlle teimS <<ri g llt liana, 一 ^ ^ 
. lsas ch.awu and is wliicli opposite hand. For example, if there are twelve articles 
^° V a か 011 (letai】， nine of t 1 em to be right hand and the remaining three 
1 バ , he order is ambiinious since it does not sav wlietlior the drawing renresentu 
ar 咖 hind 
如 d thr 
is ambiguous since it does not say wliether the drawing represents 
article oi. a left liaud article. It’ tlio order is nine required as shown, 
す ee required opposite hand no such ambiguity exists. 
Let the drawings 
__ i ron work. 
The 
of cast-iron work be separate from the drawings of 
^ . 16 P a ^ern- maker should have no use lor the wrought iron work, nor should 
I ato maker or smith be required to hunt his work out of a mass of cast 
uon wort, 
re q ^ se 1，0 uiuled corners in castings where good, strong, durable castings are 
o 1 
even 1 1 ， 0 l iU(lecl corners add strength, since the contraction on cooling is more 
üo 1 丄 h G y secure better castings, since the sand of the corners in the monltl is 
dui. 1 1 1 パ 6 免 0 】) e ' vas l ie d away into any parts of the casting ; they secure also more 
Col U'so tl aStU1 ° S 8 h】 ce tlie corners are not so liable to be knocked off l>y use. Of 
p eily . le P a ^erns with voundecl corners for rough odd castings may be too ex- 
Ull | ess ^ le above advantages are more impoitiint than Üie cost. 
⑺ • 1 ut no scale on the drawings. 
but sli G ^ 0l ^ man ^ in no case to scale the drawing, except certain full size details, 
も . ' V0l .k to tlimonsioii 3 given. Scaling a drawing is obviously wrong. If tlio 
case 'i Smau 】 ias ^^cle the drawing to scale throughout, which is not always tlio 
f ereu i ， 10 maker, fitter and smith will often on scaling dimensions give (lif- 
lf a ^ lesu 】t’ s ’ thus maliing it difficult to fit the different parts of the work togeilier. 
■^uttiurr 011 ^ lmens ^ 0u is not given the drauglitsman should be requested to give it. 
Woi.km。！ & SCa e 011 a drawing is therefore worse than useless, since it tcui, ts tlio 
to use it where dimensions have been accidentally omitted, 
rji . * ^ ccurac .Y ami completeness in execution are more valuable than dispatch. 
对 出 ha 1S 1IU gM ahnost be considered an axiom, but if based upon definite reasons it 
beco ttles e a ^ rmer hold upon the mind of the drauglitsman. An error on a di.awing 
iiig ex m ° le cos tly to make the longer the correction is delayed. Take the follow- 
边 etei. i 8 • * 加 the drawing of a cast-iron steam engine cylinder the inside (lia- 
■fiW the öl y ei m"， but on tlie drawing of the piston the diameter is given IB 7 , 
'vhicli n o miS ^ a ^° occurrec ^ apart from tlie argumeut, since mistakes do occur for 
it -will o 11 ] leaS ° n CftU veil. If tlio draughtsman sees the mistake as 80011 as made 
h wiU r- ^ cos t a fe'v moments of liis time to correct it. If tlio examiner detect it, 
W， 
• cost 
へ 4 ore c somew ^at more. If tlie workman or foreman should happen to detect it 
take • and な 111 灿叫 the piston a little more expense is incurred in correcting tlie mis- 
ted , Tvh • 卜 f • 的 Pi“ 011 a ud rings are cast, on detection much more expense is in cur- 
ia incurred ^ 咖 chined complete, ready for fitting, much more expense 
Care ， aij 山 C01rec ^ on, The argument is that the clrauglifcsman should woik with 
duty t 0 n n °^ that he should go over tlie same ground twice, as it is tlie examiners 
Us c l lee k tlie drawiug ； for it is obviously a waste of time for the examiner 
